Bastian had shown the lion the inscription on the reverse side of the Gem.
‘What do you suppose it means?’ he asked.
‘”DO WHAT YOU WISH.”
That must mean I can do anything I feel like. Don't you think so?’
All at once Grograman's face looked alarmingly grave, and his eyes glowed.
‘No,’ he said in his deep, rumbling voice.
‘It means that you must do what you really and truly want.
And nothing is more difficult.’

Michael Ende, The Neverending Story